Cleaning plug



March 24, 1931. w CROSS 1,797,823 I CLEANING PLUG Filed May 10, 192

INVENTOR.

' BY 3% I A ORNEY.

Patented Mar. 24, 1931 UNITED STATES PATENT-OFFICE 1 mm; M. (moss,oExAnsAs CITY, MISSOURI, Assmnon ,TOGASOLINE raonocrs COMPAN Ina, orJERSEY CITY, NEW JEnsEY, A oonronn'rro v or DELAWARE onnenmo rLueApplication filed May 10, T926. Serial No. 107,914.

This invention relates to improvements in cleaning plugs, and refersmore particularly to plugs adapted to be placed in the casing orassembly at the ends of tubes through which is passed liquid or fluidmedium to be heated.

Among the salient objects of the invention are, to provide an assemblyin which are cleaning plugs which are readily removable and plugs whichprevent contacting of medium with the screw or threaded joints whichserves to hold the plugs rigidly in place; to provide a double plugarrangement comprising a stationary inner'plug seated upon a taperedground joint, the angle of the joint being such as to assurepressure-tight fit and at the same time facilitate removal of the plugand a movable outer holding plug screwed in the easing into which thetubes are expanded having a convex central portion adapted to contactwith a concave portion of the inner stationary plug.

Referring to the drawings:

Fig. 1 is a sectional side view of the tube end assembly.

Fig. 2 is an end view of the assembly shown in Fig. 1.

Fig. 3 is an outer end view of the inner stationary plug.

Fig. 4; is an inner end view of the movable holding plug.

Referring to the drawings, the tubes 1 are expanded into a casing orfitting 2. Opposite the ends of the tubes are apertures havingsubstantially the same inner diameter as the tubes. These apertures orholes oppo- 4 site the ends of the tubes have tapered ground joints 3.Into these holes are fitted stationary plugs 4 which are tapered at 4 tofit the tapered ground joints 3. The outer face of the stationary orinner plug has a concave surface 5 whichis contacted by the convexsurface 6 of the outer movable holding plug 7 This outer'plug isthreaded with square threads adapted to engage the threads cut in thefitting tube. The outer faces of the holding plugs have hexagonalsockets for tightening or loosening the holding plugs by means of asocket wrench not shown.

' central threaded hole 8 drilled in the inner innerplug by means of a Ibolt which is screwed into the inner stationary .plug after the removalof the outer holding plug. The holes 9 in the outer face of thestationary or inner plug may be fitted by a spanner wrench for grindingin the surfaces of the ground seat on the fitting and plugs. The plugsused opposite the tubes are identical in construction and therefore adescription of a single plug will suflice for all. a

The use of a double plug arrangement of this character prevents theleaking of any of the medium by the inner plug to contact and corrode orclog the screw or threaded joint between the outer holding plug and thefitting; therefore, the outer plu s may be easily unscrewed or tightenedwithout tendency to freeze or become corroded in place due to the actionof chemical contained in the medium which is being treated upon thesteel. 3

Furthermore, by the use of two plug sections,one round to apressure-tight fit with the fitting, while the other functions as aholding member primarily and the threaded section is not depended uponto assure the pressure-tight closure. The wearing of threads due to acontinual removal and replacement of the plugs produces a constructionunsafe under highpressures.

As suggested, the angle of the tapered ground joint is such as to assurea pressure tight fit and permit the easy removal of the inner plugs. Anangle adapted to produce this eflect is substantially 80 from thehorizontal.

Particularly with reference to pipe stills in connection with treatmentof hydrocarbon oils, the threaded connection between plugs and tube endfittings become coked up and rigidly lodged in place so that it isnecessary oftentimes to drill out the plug from the fitting. Plugs ofthis character are adaptable to any type of heating system in which afluid medium is being treated for use in tube end fittings.

I claim as my invention:

A tube header assembly comprising a header having opposite walls, one ofsaid walls havingtube repeiving openings therein, the other wall havingcleanout openings directly opposite the tube receiving openings, a.eripheral edge of said cleanout openings belng tapered to form a plugreceiving seat, a disc-like plug having a reduced portion adapted toenter the cleanout enings, and

A an enlarged portion ground to t the receiving seat, said plugs havinga shallow concave recess formed in the outer surface thereof, tubularinternally threaded protuberances surrounding the cleanout openings,

to t e protuberances, tool receiving means formed on one side of thefollowers, and convex projections centrally formed on the inner sidethereof adapted to engage the recesses in the plugs to position andsecure the plugs in the cleanout openings. Y

' WALTER M. CROSS.

one-piece imperforate followers threaded ml

